| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * u_audio.h -- interface to USB gadget "ALSA sound card" utilities |
| 4 | * |
| 5 | * Copyright (C) 2016 |
| 6 | * Author: Ruslan Bilovol <ruslan.bilovol@gmail.com> |
| 7 | */ |
| 8 | |
| 9 | #ifndef __U_AUDIO_H |
| 10 | #define __U_AUDIO_H |
| 11 | |
| 12 | #include <linux/usb/composite.h> |
| 13 | |
| 14 | struct uac_params { |
| 15 | /* playback */ |
| 16 | int p_chmask; /* channel mask */ |
| 17 | int p_srate; /* rate in Hz */ |
| 18 | int p_ssize; /* sample size */ |
| 19 | |
| 20 | /* capture */ |
| 21 | int c_chmask; /* channel mask */ |
| 22 | int c_srate; /* rate in Hz */ |
| 23 | int c_ssize; /* sample size */ |
| 24 | |
| 25 | int req_number; /* number of preallocated requests */ |
| 26 | }; |
| 27 | |
| 28 | struct g_audio { |
| 29 | struct usb_function func; |
| 30 | struct usb_gadget *gadget; |
| 31 | |
| 32 | struct usb_ep *in_ep; |
| 33 | struct usb_ep *out_ep; |
| 34 | |
| 35 | /* Max packet size for all in_ep possible speeds */ |
| 36 | unsigned int in_ep_maxpsize; |
| 37 | /* Max packet size for all out_ep possible speeds */ |
| 38 | unsigned int out_ep_maxpsize; |
| 39 | |
| 40 | /* The ALSA Sound Card it represents on the USB-Client side */ |
| 41 | struct snd_uac_chip *uac; |
| 42 | |
| 43 | struct uac_params params; |
| 44 | }; |
| 45 | |
| 46 | static inline struct g_audio *func_to_g_audio(struct usb_function *f) |
| 47 | { |
| 48 | return container_of(f, struct g_audio, func); |
| 49 | } |
| 50 | |
| 51 | static inline uint num_channels(uint chanmask) |
| 52 | { |
| 53 | uint num = 0; |
| 54 | |
| 55 | while (chanmask) { |
| 56 | num += (chanmask & 1); |
| 57 | chanmask >>= 1; |
| 58 | } |
| 59 | |
| 60 | return num; |
| 61 | } |
| 62 | |
| 63 | /* |
| 64 | * g_audio_setup - initialize one virtual ALSA sound card |
| 65 | * @g_audio: struct with filled params, in_ep_maxpsize, out_ep_maxpsize |
| 66 | * @pcm_name: the id string for a PCM instance of this sound card |
| 67 | * @card_name: name of this soundcard |
| 68 | * |
| 69 | * This sets up the single virtual ALSA sound card that may be exported by a |
| 70 | * gadget driver using this framework. |
| 71 | * |
| 72 | * Context: may sleep |
| 73 | * |
| 74 | * Returns zero on success, or a negative error on failure. |
| 75 | */ |
| 76 | int g_audio_setup(struct g_audio *g_audio, const char *pcm_name, |
| 77 | const char *card_name); |
| 78 | void g_audio_cleanup(struct g_audio *g_audio); |
| 79 | |
| 80 | int u_audio_start_capture(struct g_audio *g_audio); |
| 81 | void u_audio_stop_capture(struct g_audio *g_audio); |
| 82 | int u_audio_start_playback(struct g_audio *g_audio); |
| 83 | void u_audio_stop_playback(struct g_audio *g_audio); |
| 84 | |
| 85 | #endif /* __U_AUDIO_H */ |